In general, fabrics with weft woven stretch are produced by inserting elastomeric yarns, crimped yarns, or high twist spun yarns into the fill direction of a fabric while weaving with a rigid warp yarn. These fabrics are subsequently subjected to fabric finishing processes that produce stretch characteristics. These desirable stretch performance fabrics are being produced in a variety of ways by exploiting the mechanics of the textile machinery as well as the structural properties of the fibers and yarns.
U.S. Pat. No. 5,858,885 to Hamilton et al (1999) builds stretch into woven fabrics with partially oriented elastomeric core-in-sheath yarns (POY). The stretched fabric is heat set in the stretched position, then immersed in an aqueous bath which results in a stretch capacity or 18% to 45% with dimensions similar to the loom state fabric.
U.S. Pat. No. 3,357,076 to Greenwald et al (1967) lists 3 processes for imparting weft stretch to woven fabrics using undrawn yarn. 1) the fabric is woven at 55″ loom-state then relaxes to 43″ and heat set in a relaxed position resulting in a 40% stretch 2) the fabric was woven to 110″ loom-state, relaxed to 48″ then heat set resulting in 215% stretch. 3) the fabric was woven to 110″ loom-state and heat set in the stretched position resulting in a 10% stretch.
U.S. Pat. No. 3,655,327 to Rollins (1972) involves a stepwise fabric process that increases the take up in the weft direction by increasing and maintaining a higher than normal warp tension throughout the weaving and finishing process. The increased weft take up produces a fill wise crimp that is heat set and results in a 20% to 35% mechanical stretch in the fill direction.
U.S. Pat. No. 3,077,655 to Runton (1963) establishes a weft stretch of 10% to 25% by weaving with open low fabric count weaves containing high twist wool yarns in the warp and fill. During finishing the yarns are compacted by alternating compaction and release with the use of a reducing agent and agitation. The shrinkage of the fabric imparts stretch by alternating compaction and release; thereby using the inherent felting ability of wool fibers through entanglement of the scale structure.
U.S. Pat. No. 2,765,513 (1956) and No. 2,765,514 (1954) both to Waton, create warp stretch woven fabric with mechanical compaction the warp direction. By feeding the fabric at a speed and co-efficient of friction differential between two nip rolls with the use of a blade, stretch is imparted by pushing the weft yarns closer together and heat setting. This essentially increases the warp take up giving the fabric elastic characteristics of 10% or greater.
It is the intent of this endeavor to produce additional performance capability in weft stretch woven fabrics that exhibits a high degree of stretch with a controlled modulus for compression and good recovery.